"Diagnostic reference level" (DRL):
introduced in 1996 by the International Commission on Radiological Protection (ICRP) (1),
updated in 2017 with recommendations on DRLs in medical imaging and clarification issues related to definitions of the terms (2).
According to ICRP publication 135 (2):
National DRLs (NDRLs) are representative of an entire country,
Local DRLs (LDRLs) are representative of a few healthcare facilities in a local area.
They consider faster local optimization processes than NDRLs and remain anatomy-based.
NDRLs and LDRLs are calculated as the third quartile...
Description of activity and work performed
5 imaging centers of the Swiss Groupe 3R (3R,
Réseau Radiologique Romand) were involved in this study.
A dose-team was set-up,
with one radiologist and one technologist in each center,
a CT field engineer,
a physicist and team leader,
aiming at standardizing protocols,
optimizing dose while maintaining image quality and creating awareness and dissemination.
Image quality was assessed using adapted European image quality guidelines (4) ( Fig. 1 ) and through an electronic image quality voting button in the dose tracking software used...
Conclusion and recommendations
This study showed that our institutional dose levels remain significantly lower than the new Swiss NDRLs published in 2018,
indicating that our quality project on harmonization and optimization of CT scanner acquisition protocols has allowed a dose optimization in line with the ALARA principle.
When considering CT scanner optimized protocols based on clinical indication,
the difference with respect to the dose metrics corresponding to anatomical region protocols are not significant for chest and significantly different only for specific indications in abdomen.
Including patient habitus would...
Institut de Radiologie de Sion
Rue du Scex,
Mail : [email protected]
International Commission on Radiological Protection (1996) ICRP publication 73: Radiological Protection and Safety in Medicine.
ICRP 26 (2).
International Commission on Radiological Protection (2017) ICRP publication 135: Diagnostic reference levels in medical imaging.
ICRP 46 (1).
Federal Office of Public Health (2018) Directive R-06-06 Niveaux de reference diagnostiques en tomodensitométrie.
Available via https://www.bag.admin.ch/dam/bag/fr/dokumente/str/std/bag-wegleitungen/2018-06-15-r-06-06.pdf.
Accessed 13 October 2018.
European Commission (1999) European guidelines on quality criteria for computed tomography.
Available via http://www.drs.dk/guidelines/ct/quality/index.htm.
Accessed 10 September 2018.